cluster,test: failing cluster+inspector test when using port 65535

[bnoordhuis]

https://ci.nodejs.org/job/node-test-commit-aix/nodes=aix61-ppc64/11932/consoleText

not ok 2069 sequential/test-inspector-port-zero-cluster
  ---
  duration_ms: 0.911
  severity: fail
  stack: |-
    Debugger listening on ws://127.0.0.1:65535/a568d00d-197e-452f-9f5a-b49ad2103d28
    For help see https://nodejs.org/en/docs/inspector
    Debug port must be 0 or in range 1024 to 65535.
    Debug port must be 0 or in range 1024 to 65535.
    Debug port must be 0 or in range 1024 to 65535.
    { AssertionError [ERR_ASSERTION]: The expression evaluated to a falsy value:
    
      assert(ports.every((port) => port < 65536))
    
        at Promise.all.then.common.mustCall (/home/iojs/build/workspace/node-test-commit-aix/nodes/aix61-ppc64/test/sequential/test-inspector-port-zero-cluster.js:38:7)
        at /home/iojs/build/workspace/node-test-commit-aix/nodes/aix61-ppc64/test/common/index.js:537:15
        at <anonymous>
        at process._tickCallback (internal/process/next_tick.js:120:7)
      generatedMessage: false,
      name: 'AssertionError [ERR_ASSERTION]',
      code: 'ERR_ASSERTION',
      actual: false,
      expected: true,
      operator: '==' }

Note the ws://127.0.0.1:65535/. The test randomly picked port 65535, then tries to spawn additional processes that bind to consecutive ports, which of course fails.

There are probably more tests that suffer the same issue but it's arguably also a bug in the cluster module because it happily picks ports > 65535 for workers.